From: mailslot at mac dot com Operating system: Linux 2.4.21-9.EL PHP version: 5.1.2 PHP Bug Type: Reproducible crash Bug description: Can cause open-ended exception bomb
Description: ------------ I encountered this problem while debugging an exception logging class. Infinite recursion problems are a coding mistake, but I've never seen one take down Apache before. Apache will grow in size until virtual memory starts swapping. The CPU will be at 100% and eventually, appears to halt. Limits, obviously, are not being used... yet. Reproduce code: --------------- <?php class Eggception extends Exception { public function __construct($ex) { parent::__construct($ex); try { // let's say that a database object throws derived Eggception throw new EggceptionSubclass('It happens'); // this is valid (not infinitely recursive) //throw new Exception('It happens'); } catch (Exception $e) { // should swallow exception, right? // not before a never-ending recursive bomb } } } class EggceptionSubclass extends Eggception {} // the following causes a runaway process (memory leak & // CPU spike) with Apache 2.0.55 and PHP 5.1.2 // rather quickly, all server resources become exhausted // without proper process limits, potentially crashing the // entire machine. throw new Eggception('Exception Bomb'); ?> Expected result: ---------------- A timeout after a large CPU spike... perhaps a stack overflow error. An exception recursion counter that kills a script whenever it's 1,000 layers deep in an exception stack... that would be great. Actual result: -------------- The process (PHP or Apache, depending on which are used to execute the script) will consume as much memory allowed while pegging the CPU at 100% utilization. Kill -9 works fine. Workarounds include ulimit and softlimit. -- Edit bug report at http://bugs.php.net/?id=37204&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=37204&r=trysnapshot44 Try a CVS snapshot (PHP 5.1): http://bugs.php.net/fix.php?id=37204&r=trysnapshot51 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=37204&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=37204&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=37204&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=37204&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=37204&r=needscript Try newer version: http://bugs.php.net/fix.php?id=37204&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=37204&r=support Expected behavior: http://bugs.php.net/fix.php?id=37204&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=37204&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=37204&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=37204&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=37204&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=37204&r=dst IIS Stability: http://bugs.php.net/fix.php?id=37204&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=37204&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=37204&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=37204&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=37204&r=mysqlcfg